In the past, various techniques have been proposed and used for purposes of animal identification. The techniques of branding and tattooing of animals are well known. Animal markers such as ear tags and back tags have been used for identification. In addition, it has been proposed to use coded markers or tags embedded under the hide or skin of the animal. See, for example, Todd U.S. Pat. No. 487,304, Dobyns U.S. Pat. No. 881,062, Bagby U.S. Pat. No. 1,257,065, Johnston U.S. Pat. No. 1,318,283 and Jefferts U.S. Pat. No. 3,545,405. In addition, the marking of meats and other food products by insertion of an edible substance is disclosed in Rath U.S. Pat. No. 1,859,467.
For purposes of swine identification, the United States Department of Agriculture has published a proposed rule in the Federal Register, Vol. 53, No. 22, page 3154, dated Feb. 3, 1988, 9 C.F.R. .sctn.71.19, requiring all swine to be identified in interstate commerce. The approved means of swine identification include ear tags, back tags, tattoos, ear notching and ear tattoos. These approved means suffer from the following disadvantages.
Back tags have limited life and can be rubbed off easily. Additional labor is required at the slaughtering plant to transfer the identifying information before dehairing of the swine. Also, a secondary identification device is required after dehairing and singeing of the swine. The integrity of identity is subject to errors and omissions due to the potential loss of the back tag from a live animal and the required transfer of information during slaughter. Expensive labor is required at the slaughter plant to transfer information.
Ear tags are costly to apply, labor intensive, and difficult to read at a distance. A secondary identification device is required when the ear tag is removed during slaughter. It is subject to loss during transit and slaughtering of the swine. The integrity of identity is subject to errors and omissions during the transfer of information to a secondary identification device during slaughter. Expensive labor is required at the slaughter plant to transfer the information.
Tattoos exhibit problems with legibility when improperly applied to the swine. The identifying information can be lost during trimming/or skinning operations. A tattoo is subject to duplication, does not lend itself to sequential numbering, and is messy to apply.
Ear notching and ear tattooing require registration in a national breed register which is not possible for crossbred animals. This requirement only applies to breeding stock, not market hogs. Some purebred breeds are difficult to recognize as a carcass. Ear notching is subject to duplication and subject to error because of notches improperly positioned in the ear. Ear notching and ear tattooing are costly because of the registration fees required. Also, older animals tend to develop torn ears, reducing the legibility of ear notches and ear tattoos.
In view of the difficulties discussed above, an identification system for swine or other livestock which is easily applied and capable of accurate identification of both live animals and carcasses is desirable. In addition, it is desirable that the identification system be biologically compatible with the swine or other livestock and easily disposable after the slaughter of the animal.